Bitmap: regenerate GdkTexture when Canvas was used on the Bitmap

src/api-impl-jni/android_graphics_Bitmap.c

@@ -158,3 +158,9 @@ JNIEXPORT void JNICALL Java_android_graphics_Bitmap_nativeCopyPixelsToBuffer(JNI
 	memcpy(pixels, gdk_pixbuf_get_pixels(pixbuf), pixbuf_size);
 	release_nio_buffer(env, array_ref, array);
 }
+
+JNIEXPORT void JNICALL Java_android_graphics_Bitmap_native_1unref_1texture(JNIEnv *env, jclass class, jlong texture_ptr)
+{
+	GdkTexture *texture = GDK_TEXTURE(_PTR(texture_ptr));
+	g_object_unref(texture);
+}

src/api-impl-jni/generated_headers/android_graphics_Bitmap.h

@@ -67,6 +67,14 @@ JNIEXPORT jlong JNICALL Java_android_graphics_Bitmap_native_1create
 JNIEXPORT jlong JNICALL Java_android_graphics_Bitmap_native_1paintable_1from_1pixbuf
   (JNIEnv *, jclass, jlong);
 
+/*
+ * Class:     android_graphics_Bitmap
+ * Method:    native_unref_texture
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_android_graphics_Bitmap_native_1unref_1texture
+  (JNIEnv *, jclass, jlong);
+
 /*
  * Class:     android_graphics_Bitmap
  * Method:    nativeCopy

src/api-impl/android/graphics/Bitmap.java

@@ -1607,13 +1607,24 @@ public final class Bitmap {
 		return texture;
 	}
 
+	/**
+	 * internal ATL method to destroy the cached GdkTexture when the Bitmap was touched 
+	 */
+	public void destroyTexture() {
+		if (texture != 0) {
+			native_unref_texture(texture);
+			texture = 0;
+		}
+	}
+
 	//////////// native methods
 
 	private native long native_bitmap_from_path(CharSequence path);
 	static native long native_copy(long src);
 	static native long native_subpixbuf(long src, int x, int y, int width, int height);
 	private static native long native_create(int width, int height);
-	public static native long native_paintable_from_pixbuf(long pixbuf);
+	private static native long native_paintable_from_pixbuf(long pixbuf);
+	private static native void native_unref_texture(long texture);
 
 	private static native Bitmap nativeCopy(int srcBitmap, int nativeConfig,
 						boolean isMutable);

src/api-impl/android/graphics/Canvas.java

@@ -9,6 +9,7 @@ public class Canvas {
 	public Canvas() {}
 
 	public Canvas(Bitmap bmp) {
+		bmp.destroyTexture();  // invalidate cached texture
 		this.skia_canvas = native_canvas_from_bitmap(bmp.pixbuf);
 		this.widget = 0;
 	}